In a conventionally known slot machine, a symbol display region in which a plurality of cells are arranged in longitudinal and lateral directions is provided on a front surface of a casing, and a physical or virtual reel is disposed with respect to each of cells or each of cell columns arranged in a predetermined direction. On the reel, plural kinds of symbols, each of which represents a numeral, a drawing pattern or the like, are arranged in predetermined alignment order, and thus each of the reels serves as a symbol column. A game is started when a player deposits coins or alternative coins such as medals, tokens, or the like, performs betting operation, and further instructs a game start. In connection with the game start, the reels start to spin along the cell columns. If a predetermined stop time comes, the reels are stopped in such a manner that one symbol appears on each cell or in a manner that symbols appear together on one cell. When a combination of symbols which are stopped on cells in a predetermined cell group satisfies a predetermined prize winning condition, for example, a prize winning pattern made up of the same symbols on a predetermined prize winning determination target line is formed, a dividend according to the prize winning pattern is provided to the player.
In the above described type of slot machine, dividend rates are differentiated from each other according to kinds of symbols. When a specific symbol appears, probability of forming a prize winning pattern may be increased, or a relatively high dividend may be generated. Such symbol is recognized by a player as a symbol that is advantageous for obtaining a dividend. If such symbol appears, it can raise a player's expectation for obtaining the dividend. Accordingly, in order to raise the player's expectation for obtaining a high dividend, there is proposed a gaming machine in which a symbol with advantage for obtaining dividends remains as a fixed symbol in a symbol display region when such symbol appears and stops on a cell at one game opportunity, and, at the next game opportunity, symbols are changed in portions other than the fixed symbol (for example, refer to Patent Document 1).    [Patent Document 1] US2009/0215519A1